Injury compensation lawyer Taren Point: impairment explained

In everyday speech, a serious injury is one that hurts a lot or takes a long time to heal. The CTP scheme uses narrower tests. The first is whether the injury is more than a threshold injury. The second, for some kinds of compensation, is how much permanent impairment it leaves, measured as whole person impairment. Pain matters to you, but the scheme looks at diagnosis and lasting effect.

Whole person impairment, or WPI, is a percentage that describes how much a lasting injury affects the body as a whole. It isn't a measure of pain, and it isn't a measure of what you've lost. It's a medical assessment made under set guidelines once an injury has stabilised. In a CTP claim, WPI matters mainly for damages: non-economic loss is only available where WPI is more than 10%.

It's easy to overstate the 10% line. You don't need more than 10% WPI to claim damages for past and future loss of earnings; you need an injury that's more than threshold, another driver at fault, and not to have been mostly at fault yourself. The 10% line decides pain and suffering, and it also affects some timing rules for a damages claim.

Weekly payments cover lost income for a limited time. For a serious injury, the bigger question is the future: will you be able to return to your old job, at the same hours and pay? If not, a damages claim may include past and future economic loss, provided the conditions for damages are met. That part of a claim doesn't depend on WPI above 10%.

There's usually no single moment when WPI is measured. Opinions may come from treating doctors, from doctors the insurer arranges, and, where the two sides disagree, from a medical assessment through the Personal Injury Commission. Timing matters, because injuries can improve or worsen for months. A lawyer can advise whether an assessment is premature before you rely on it.

• Whether every injured body part is included
• Scans or tests your doctors have ordered
• Whether you disagree with the result, and the deadline to say so

The threshold line is a medical line drawn by legal rules. Your doctor diagnoses the injury; the scheme's definition decides which side it falls on. Sprains, strains and whiplash without nerve findings usually sit on the threshold side. Confirmed nerve damage, a tear, a fracture or a brain injury generally takes an injury beyond it. The insurer makes the call, and you can challenge it.

Getting the classification right early helps. If you have symptoms that could point to nerve involvement or a tear, such as numbness, weakness, locking or a joint giving way, describe them to your doctor. Whether tests are needed is a medical decision. If a diagnosis changes, make sure the insurer has the new evidence, because the classification may need to change with it.

A crash can cause psychological injury as well as physical injury, and sometimes instead of it. Some psychological injuries are classed as threshold injuries; others are not, depending on the diagnosis. Anxiety, low mood, flashbacks or fear of driving are worth raising with your GP early, both for your own sake and so the injury is recorded and properly diagnosed.

Because serious injuries take time to show their full effect, evidence builds in layers. Early records show the injury happened and how bad it was. Later reports show how it has settled and what it has left behind. An independent lawyer can help spot gaps, but the underlying evidence comes from your treatment. Getting good care is also how good evidence is made.

• Hospital admission and discharge records
• Imaging reports, such as X-ray, CT or MRI, where done
• Operation and specialist reports
• Reports from a treating psychologist or psychiatrist, if any